Bicyclist&#39;s helmet



FIG. 1 is a top plan view of a bicyclist's helmet showing my new design;

FIG. 2 is a side elevational view, the opposite side being a mirror image thereto;

FIG. 3 is a front elevational view thereof; and

FIG. 4 is a rear elevational view thereof. 

The ornamental design for a bicyclist's helmet, as shown and described. 